VATICAN CITY — A Vatican judge on Monday ordered the pope's butler and a fellow lay employee to stand trial for allegedly pilfering documents from Pope Benedict XVI's private apartment, a scandal that embarrassed the Vatican and exposed infighting and alleged corruption at the highest levels.

The indictment accused Paolo Gabriele, the butler arrested at the Vatican in May, of grand theft, a charge that carries one to six years in jail on conviction if the pope does not choose to pardon his once-trusted aide.

While the Vatican had insisted throughout the investigation that Gabriele, a 45-year-old married laymen who lives with his family in Vatican City, was the only person under investigation, the indictment also orders trial for Claudio Sciarpelletti. He is a 48-year-old layman and computer expert in the Secretariat of State office and is charged with aiding and abetting Gabriele.

The Vatican has promised a public trial. Vatican spokesman the Rev. Federico Lombardi said both defendants would be tried together before a three-judge panel, in late September at the very earliest, since the Vatican tribunal is on summer recess until. Sept. 20. A trial date is expected to be announced after the court resumes work.

The Vatican has been on the defensive ever since documents alleging corruption and exposing power struggles began appearing in the Italian media — in print and on TV — in January. In May, a book by an Italian journalist was published containing dozens of documents from the pope's desk, including letters written to Benedict.

Lombardi said the magistrates didn't take on the bigger task of grappling with the wider, more serious issue revealed by the leaked documents— alleged corruption within the top ranks of the church. He sidestepped a question of whether a special panel of cardinals Benedict set up to deal with the scandal had made any inroads into the wider question of moral wrongdoing among higher-ups.

In the 20-page indictment, Judge Piero Antonio Bonnet ruled that there was no evidence to indict Sciarpelletti — a computer expert in the secretary of state's office who knows Gabriele — on a charge of revealing secrets and insufficient evidence for a charge of grand theft.

There had been widespread speculation about the possibility of a mole in the secretary of state's office since some of the leaked documents seemed aimed at casting doubt at Cardinal Tarcisio Bertone's ability to be the Vatican's No. 2 as secretary of state.

One of the psychological experts who examined Gabriele during the probe concluded that the pope's butler was unsuited for that job, which went from dawn to dusk and included serving the pope meals, helping him get dressed, attending morning Mass with Benedict and other assignments, according to the indictment. Gabriele developed "a grave psychological unease characterized by restlessness, tension, anger and frustrations."

Vatican investigators found a "mountain of documents" in Gabriele's Vatican apartment that had been taken from the pope's apartment, Lombardi said. Among them was a check for €100,000 ($123,000) made out to the pope from a Catholic university. Gabriele said that in the "disorder" of all the documents he lugged to his private apartment, "it's possible" that the check and other valuables were among the papers.

In what might help Gabriele's defense, the indictment said the defendant was motivated by a "desire to act on behalf of his personal ideal of justice," and his personality made him easily manipulated by others he considered his friends and allies."

The indictment quoted Gabriele as telling investigators that he was "motivated by my deep faith and by the desire that in the church light is shed on everything."

In his request for an indictment, prosecutor Nicola Picardi quoted the butler as saying in one of his interrogations, in early June, while under arrest that "seeing evil and corruption everywhere in the Church ... I was sure that a shock, even a media one, would have been healthy to bring the Church back on the right track."

Gabriele spent several weeks in isolation in a Vatican security cell before being placed under house arrest over the summer. Lombardi said a criminal sentence would depend "on any possible pardon" from the pope, but added that "it's premature to speak of this now."

Sciarpelletti's office was searched on May 24, hours after Gabriele's arrest. He was arrested and spent one night in a Vatican security cell, but was quickly released when it appeared clear that his role wasn't a key one in the case, Lombardi said. The Vatican had steadfastly insisted the only known suspect was Gabriele.

"You can't speak of an accomplice in any way, but he was an acquaintance who could help Gabriele" in the butler's activities, Lombardi said. The indictment noted that in Sciarpelletti's desk was found a plain white envelope, sealed, with "Personal P. Gabriele" on the front and with the Secretariat of State's stamp on the back.

Sciarpelletti has been suspended, with pay, from his job, the spokesman said.

Federico Lombardi indicated the probe was only "partially completed," leaving open the possibility that there could still be more developments.

Benedict reviewed the indictment and other documents in the probe, and Lombardi added that the pope could intervene in the case, but noted he hasn't done so to date.

The indictment quoted Gabriele as saying he made photocopies of the documents he gave to the Italian author Gianluigi Nuzzi and gave the copies to his "spiritual father," or private confessor. Lombardi said the priest, who is identified only as "B'' by the prosecutor, burned those copies.

Gabriele was also found to be in possession of a rare, 16th-century edition of Virgil's Aeneid, but defended himself saying that he had asked the pope's private secretary permission to bring it home so he could show it to his son's school professor.